Introduction

Definitions

Free Length: The length of your spring without any load.

Preload: The length you compress the spring from it’s freeload length.

Race Sag: The extended length (measured between the swinging arm and the rear fender) minus the compressed length with the rider on the cycle.

The most basic of the basics is having the tools needed to do the job.  Get a service manual for your bike. The pro mechanics have to use them, so do you, even more so.  Get a torque wrench.  You do not need an expensive one - a 1/2” beam unit is perfect.  Have an assortment of good hand tools: sockets, wrenches, screwdrivers, punches, hammers, hacksaw, etc.  You will need a work stand to get the cycle up in the air.  A ruler - I use one with inch markings because it is hard to find one with inches and metric that is over 30” long.  You will need some chemicals:  water proof grease, carb cleaner, WD40 or alike, chain oil, air cleaner oil, etc.

Now let’s get started with the basic suspension work - servicing the swinging arm, linkage, and shock bearings.  If this stuff is not properly serviced, greased, smooth operating, and no worn parts, the best spring and valved shock will not work properly.  If the bearings are rusting, frozen, or worn, you will not be able to get proper race sag, proper spring rates, or a properly adjusted shock.

Who needs to do this maintenance?  If you just bought a new cycle, take it apart and do the service.  The factories do not do a good job of lubing the bearings and using waterproof grease.  If your present cycle has not had this service and inspection done within the last 5 months, do the service. If you recently purchased a used cycle, do the service and be prepared to buy some parts. This maintenance should be done every six months, and sooner if you use a pressure washer.  A simple test is to have the cycle up on a stand so that the rear wheel is off the ground.  Grab the top of the wheel, at 12 o’clock, and lift up on the wheel.  If you have free play, you have wear starting.  Take it apart and inspect and replace worn parts and properly service and re-torque all parts.

While you have everything apart and servicing the linkage, take the shock off.  Loosen the spring up and measure the free length (length of the spring with no load) of the spring.  Then reset the preload (compression of the spring from free length) on the spring to 1/2” on linkage systems and 1/4” on non-linkage systems and most Honda XR’s.  If the spring is proper for your weight, the race sag (see definition above) will be within + or – 1/4” on linkage systems and 1/8” on non-linkage systems and most Honda XR’s.  Also while the shock is off have it serviced if the cycle is over 9 months old or you just purchased it used.  If it is a new cycle, have the nitrogen pressure recharged to factory specs.